Tagged Questions

one of the four known fundamental forces of nature and the one responsible for beta-decay radioactivity. The weak interaction is very short-ranged and more weakly coupled than either the strong nuclear force or electromagnetism. At energy scales above the Z mass the weak and electromagnetic ...

I found the matrix element in a scalar interaction $\nu_ee \rightarrow \nu_ee$ to be $$M=\bar{u}(\nu,q_2)u(e,p_1)\bar{u}(e,p_2)(1-\gamma_5)u(\nu,q_1)$$
But I do not know how to find the $|M|^2$ and ...

Of course, the $\mathrm{\rho^0}$ meson can decay in $\mathrm{\pi^{+}\ \pi^{-}}$ through the strong interaction. Using Feynman diagrams, I cannot understand why the same decay couldn't happen through ...

For the Decay $$ \pi^+ \to \mu^- \bar{\nu}_\mu $$ the Feynman rules for this tell us that the vertex couples with $\gamma^\mu (1-\gamma^5) / \sqrt{2} $. This gives me the reduced amplitude of
$$ M = ...

I learned for the first time in Eric Scerri's new book A Tale of 7 Elements that $\beta$ decay does not occur for elements with atomic number, Z > 100. I did some further web research on this subject ...

What is the piece of theory which dictates that electrons interact via the weak force with other electrons and protons, and how can this force be understood in terms of what I am more familiar with ...

This paper (I don't know if it is available for free or not) defines the axial-vector coupling constant (a constant important in calculations involving the weak interaction) as $g=1.26$. My advisor ...

I was reading about the evidence of lepton flavour violation coming from the observation
of neutrino oscillations, and was wondering whether this could also lead to LVF in weak interactions or not. ...

Intuitively, it seems as though the reason would be a small value for the coupling constant, as the probability for emitting $W^{-}$ bosons would be low. However, it's value is almost the same as the ...

I've recently been reading about how the Weak Force holds quarks together to make protons and neutrons. But before learning about that specifically, I found out about Quark-Gluon Plasma, leading me to ...

Until reading the Phys.SE post here about the neutron decay I never feel strange the fact about the antisymmetricity of this decay. But indeed why this decay is antisymmetric. The neutron is his own ...

What is the parity eigenvalue of the $W^{\pm}$ boson, or is it even an eigenstate? I have not found any source that discusses this. I have seen some lists of particles with their parity eigenvalues, ...

In short, are there cases where the weak interaction between two neutrinos is actually smaller, in (absolute) magnitude, than their gravitational interaction?
There is no principle that forbids this. ...

I have heard that Neutrino is the only particle affected by the Weak Interaction.
How is a Neutrino affected by Weak interaction? I would like to ask the detail.
Are there any relationships between ...

This is homework problem:
Given the cross-section of a neutrino-electron scattering, what is the probability for a solar neutrino to scatter with a electron as it goes through the center of the Earth?
...

A weak current of the form: $$j^\mu=\bar u_e \gamma^\mu \frac{1}{2}(1-\gamma^5)u_\nu$$ implies that it automatically selects the left-handed neutrino. This current can also be written as: $$j^\mu=\bar ...

How can a neutrino turn a neutron into a proton? This is the equation,
$$ \nu_e + n \to p + e^- \,.$$
If you draw the Feynnmann Diagram which I attempted here, "Diagram" there isn't an exchange that ...

I am studying the history of Modern Physics and Yang-Lee earned their Nobel the next year after the Cobalt experiments. I am familiar with the chronology, but am not clear what those findings meant to ...

My understanding is that the exchange of Z bosons could yield an attractive or repulsive "force" between two fermions. For most combinations the electromagnetic or strong interactions will take place.
...

As far as I have understood, the mass $m$ of a fermion causes a coupling of the both chiralities $\psi_L$ and $\psi_R$. This coupling would induce an oscillation of the chirality within a time scale ...